How to get a pointer to C++ object from wxLua object?

[sokolas]

Hi!

I would like to send events to the wxFrame created in Lua from another thread from C++. According to the wxWidgets docs, I need the thread-safe wxEvtHandler::QueueEvent method. However, in order to use it, I need a pointer to an instance of wxEvtHandler (in my case, a wxFrame or wxApp, doesn't really matter).

The docs say that wxLua userdata objects have a special metatable, and its __tostring method:

print(wx.wxPoint()){.lua} prints "userdata: 0x858df5c [wxPoint(0x84ab550, 251)]", where 0x858df5c is the Lua userdata address, 0x84ab550 is the address of the wxPoint object

Is it possible to extract that pointer from wxLua userdata objects to pass it to my C++ code?

[sokolas]

This doesn't answer the initial question in general, but for my use case, I could use wxTheApp static variable that points to the same wxApp.
It's also possible to use wxApp::GetGUIInstance for the same purpose, or wxApp::MainTopWindow for the main window.